How can i rotate both turret cannon and body same time or separate ?

I have in the Hierarchy a Turret and as a child also a Cannon. of the Turret.
Then i have a Cube i'm using for testing to see if and when the turrer detecting it and rotating facing the cube.

The problem is that if i put the Cannon as child of the Turret and the script is on the Turret it will rotate with lag. But if i put the script only on the Cannon then the Cannon will rotate fine facing the Cube but the Turret body will not rotate.

I want to rotate both Turret body and Cannon together.

I recorded a small video showing the problem.
First when the script is attached to the Cannon and then when the script is attached to the Turret.

I would attach the cannon to the turret, when the turret moves the cannon will move with it, this is how turrets work in reality. However if you did want to move the cannon and turret separately in sync then you need to move it's position and rotation.